A wide variety of lubricating oils are prepared and used in many different applications. Such lubricating oils require replacement over time once they meet their useful life expectancy. In some instances, the lubricating oils may be reprocessed by re-refiners to provide useful lubricants. However, for many applications, the lubricating oils have very little value or may be too contaminated to reprocess efficiently and thus are burned in incinerators as a means of disposal.
As sources of energy tighten globally, the use of used oil as a fuel source is becoming a more viable option for replacement or supplementation of other fuel sources. Waste or used oils, however, typically have low fuel value. Accordingly, there is a need for new uses for waste lubricating oils that may provide an increased value for an otherwise low value commodity.
The disclosure is directed to a method of enhancing a fuel value for a used or waste lubricating oil, lubricating oils having improved combustion and emission characteristics, and a business method for distributing and using waste oils as components of primary combustion fuels. In one embodiment, there is provided a lubricating oil composition having improved combustion properties when burned as a used lubricating oil composition. The lubricating oil composition includes a major amount of oil of lubricating viscosity and a minor combustion improving amount of a combustion improving additive.
Another exemplary embodiment provides a method for improving a fuel value of a used lubricating oil. The method includes combining a combustion improving amount of a combustion improving additive with an oil of lubricating viscosity and using the oil of lubricating viscosity.
Yet another exemplary embodiment provides a method of doing business. According to the methods, an oil of lubricating viscosity is leased to a user. The oil of lubricating viscosity contains a combustion improving amount of combustion improving additive. Used oil is collected from the user and sold as a fuel component.
Another embodiment provides a method for reducing the vapor pressure of an organometallic additive concentrate. The method includes formulating a used oil of lubricating viscosity with an amount of organometallic additive sufficient to provide from about 0.1 to about 10,000 ppm total metal to the additive concentrate. The resulting additive concentrate has a vapor pressure of less than about 0.0005 torr at 20° C. and less than about 0.50 torr at about 120° C.
An advantage of embodiments of the disclosure is that lubricants and oils typically having low fuel values may be greatly enhanced before use so that upon replacement of the lubricants, the lubricants may be used as an alternative fuel source. The embodiments also provide a unique method of providing increased value for lubricants used in industrial applications by providing a leasing rather than sales model that enables the lessor to reclaim the lubricant periodically and sell the lubricant for fuel value. A further benefit of the disclosed embodiments is that, compared to burning lubricants devoid of the combustion improving additive, lubricant compositions as described herein may have increased emissions lowering properties. Another advantage of the compositions and method described herein is that organometallic additive concentrates may be provided that have relatively low vapor pressures thereby improving the handling and storage capabilities of such additive concentrates.